Currently, the United States Air Force and Navy operate air combat maneuvering ranges at specific sites around the world. At the smaller ranges, aircraft only engage other aircraft in simulated air-to-air combat. At the larger ranges, they also are able to engage ground targets. (In addition, the Navy has at-sea (off-shore) and under-sea training ranges with complex fixed tracking infrastructures.) Simulation is accomplished by the use of dynamic flyout models of ordnance fired by the aircraft. Factored in the model is the position, orientation and velocity of the aircraft and the target at the time of simulated launch of the missile and the properties of the missile propulsion and guidance systems.
Each of these ranges includes a network of ground based transmitter/receiver sites and a central control facility. A pod on each aircraft includes equipment to provide communication with the ground based sites to provide location information and weapons deployment information. A central computer at the central control facility uses the signals received by the ground stations to determine the position of each aircraft by multilateralization techniques. Upon receipt of weapon deployment information, the central computer runs a missile model to determine whether the ordnance hit the intended target. The hit or miss information is then communicated via the ground stations back to the aircraft and the aircraft crew. The central computer can also store and later retrieve and display the data regarding the movements of the aircraft and all weapons deployments and results.
A number of disadvantages of this system result from limitations of the ground based signal transmitter/receivers. Training is limited to specific air combat maneuvering range locations. The ranges are bounded by the transmitter/receivers and the transmitter/receivers must be located sufficiently close together to provide signals for accurate positioning of the aircraft. Therefore, the number of transmitter/receivers limits the size of the ranges. Increasing the number of transmitter/receivers, also increases the complexity and costs.
Furthermore, line-of-site requirements for signal transmission prevent use of hilly terrains for an air combat range and prevent low level flight maneuver training. Although the ground based transmitter/receivers need to be widely distributed to cover a larger flight area, they also need to communicate with the central computer and to be accessible for maintenance and repair. Therefore, areas within a maneuvering range where engagements can take place may be limited.
There is no practical way to set up maneuvering ranges far out at sea to allow for combat engagement training of Navy pilots. Even if there were, since fleet exercises occur over very large areas, such a range would necessitate a excessive number of transmitter/receivers mounted on floating platforms. Therefore, the Navy is forced to rely on land-based or close, offshore ranges and is unable to conduct the desired air combat training when at sea.
Due to the large number of platforms, threats and engagements, a very large number of calculations are required by the central computer. It must have a large memory storage and computation capacity. The computational complexity and the number of transmitter/receiver sites limits the number of aircraft which can be monitored. Current systems can handle about twenty to thirty-six aircraft. Present plans call for the number to be expanded to one hundred at major ranges such as the Air Force's Red Flag range and the Navy's Fallon range. This will entail a significant increase in ground stations and computer capability.
The costs of constructing and maintaining a maneuvering range are very high. A large number of widely dispersed transmitter/receivers need to be constructed and maintained. The transmitter/receivers require direct connections, through relays or land lines, to the central computer to provide the computational information. The large memory and computing needs for the central computer also increase the costs.
As a consequence of the above deficiencies, fewer ranges are available to meet desired training objectives, and the training is expensive. For widely dispersed or remotely located units, such as Air Reserve Forces or Naval Forces at sea, ranges are relatively inaccessible. When range time is available, these units must accomplish a costly deployment to the range location. For forces temporarily stationed around the world for peacekeeping missions, prewar deployments, or other reasons, all training must be suspended due to the lack of training ranges in most areas of the world.
Recently, the military has been considering a revised combat maneuvering range which would use the Global Positioning System (GPS) satellites in conjunction with an Inertial Reference Unit (IRU) for determining the position of each aircraft. The GPS is a constellation of orbiting satellites that generate signals indicative of the satellite position. Each aircraft would be fitted with a GPS receiver pod which receives signals from a number of satellites and performs its own multilateralization calculations to determine its position. A ground station would provide another GPS signal for providing the aircraft with more accurate position information with respect to the ground. The pod on each aircraft would then transmit its position to the ground based transmitter/receiver sites. Under this system, the central computer would be relieved of the position triangulation computations for the aircraft. However, it would still perform all of the other functions, and thus ranges would still be limited by the physical location of the transmitter/receiver sites (including relays), line-of-sight considerations, the computational capacity of the central computer, and high maintenance costs.
Therefore, a need exists for a air combat system that is not restricted to specific ground locations, which requires a simple, less expensive ground infrastructure, and whose operations and maintenance costs can be significantly reduced. Another need exists for a system which can be used over the ocean for training of ship-based aerial engagements. Another need exists for a system which can be used in conjunction with non-aircraft based threats such as ships, surface-to-air missiles (SAM), land-based targets (both fixed and mobile), and electronic warfare systems.